/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
Called before creating a PIE server instance.
virtual [FGameInstancePIEResult](API\Runtime\Engine\Engine\FGameInstancePIEResult) PreCreatePIEServerInstance ( const bool bAnyBlueprintErrors, const bool bStartInSpectatorMode, const float PIEStartTime, const bool bSupportsOnlinePIE, int32 & InNumOnlinePIEInstances )